Here's the news from 1991 – a vanishingly small number of peer-reviewed studies in science journals argue that humans aren't the cause of global warming.

Here's the news from 2013 – since 1991, less than two per cent of all peer-reviewed studies say climate change is caused by something other than human activities (that's burning fossil fuels and digging up forests, to you and me).

So after giving up on the peer-reviewed literature, the climate science contrarians – often bolstered by support from the fossil fuel industry and free-market idealogues - took their talking points somewhere else.

That is, out into the public domain, the mainstream media and the blogosphere and far away from the less forgiving operating theatre of peer-reviewed science journals.

To this day, these dead theories hang around like slack-jawed zombies in the graveyards of global media outlets.

Take a recent column published in the Wall Street Journal, for example, which tried to claim that global warming was down to natural cycles and changes in the sun's output. Carbon dioxide was just food for plants, wrote the authors.

Or how about London Mayor Boris Johnson's column earlier this year in The Daily Telegraph, where he also claimed climate change was driven by the sun. Johnson often quotes his "old chum" Piers Corbyn, a long-range weather "forecaster" who claims CO2 has no effect on global temperature.

In the US, the Union of Concerned Scientists has looked at climate change coverage in the Wall Street Journal and on Fox News over a six-month period. In the case of Fox, UCS classified 37 out of 40 segments as "misleading" on climate change science. In almost a year of Wall Street Journal articles, just nine out of 48 articles were deemed to accurately reflect the state of the science.

Then there is the near omnipresence of free market conservative think-tanks – funded variously through secretive channels or the largesse of fossil fuel interests – who write books, columns and are asked to be "expert" commentators on climate change.

The current issue of the journal American Behavioral Scientist (ABS) is devoted to the phenomenon of climate change scepticism and denial and brings together studies and essays looking at the role of the media in trying to keep alive those climate change theories which have been under permanent cardiac arrest for the last two decades or more.

The authors, Professor Riley Dunlap and Shaun Elsasser, both of Oklahoma State University, looked at 203 columns written by more than 80 conservative writers published between 2007 and 2010. The authors conclude:

The overall results reveal a highly dismissive view of climate change and critical stance toward climate science among these influential conservative pundits. They play a crucial role in amplifying the denial machine's messages to a broad segment of the American public.

Similarly self-explanatory were some of the titles of the columns they investigated. There was "The Global Warmists' Deceit", "It's Got to Suck to Be a Climavangelist", "Hoax of the Century" and "Four Colossal Holes in the Theory of Man-Made Global Warming."

Dunlap and Elsassser also tally-up and categorise the arguments used to dismiss the science or dismiss the need to act. And the most common climate science denial argument used? "There is no consensus".

In an essay in the same issue of ABS, Maxwell Boykoff, an assistant professor at the University of Colorado, notes how accurate media coverage alone won't be the panacea for genuine policy action to cut emissions. He adds:

But improvements in reporting on claims and claims makers will help. The fossils of climate science and policy decision-making as well as communications may choose to continue along with the status quo. But to more effectively inform and engage - rather than confuse and bewilder - the public, 21st-century journalists and editors, as well as researchers, scientists, policy actors, and other non-nation-state actors, need to acknowledge the disproportionate influence of these outlier voices in mass media and communicate climate change with greater specificity and context.

While some media outlets have given their consumers the impression that climate scientists are split on the causes of climate change, the pulse of actual scientific debate on this issue faded long ago.

At least now, readers can be more certain that when they hear that climate change might not be caused by humans, it's probably just a zombie theory.